I have seen a couple of bride melt downs in my own family. I think it's because they dream for years what every minutest detail of their wedding day will be like, without factoring the real world into it at all. I think it's some kind of weird queen complex or something... and then, of course, the dream never manifests, and it becomes the fault of everyone else, and not down to the bride's unrealistic expectations at all. Totally crazy. Women seem to loose all their marbles that one day. It is tragic, when within their own mind, they turn what should be their happiest day into their saddest.
I guess some women feel a massive pressure - getting married, to some, means becoming of value in society, and it has to be done just so. As if life isn't difficult enough already.